Protection Mode

Safety

Disconnect all electric power, including remote disconnects before servicing. Follow proper lockout/tagout pro- cedures to ensure the power cannot be inadvertently energized. Failure to follow recommendations could result in death or serious injury.

1.Control signals from, or internally within, the adjustable frequency drive may in rare cases be activated in error, be delayed or fail to occur entirely. When used in situations where safety is critical, e.g., when con- trolling the electromagnetic brake function of a hoist application, these control signals must not be relied on exclusively.

Note

When using the Safe Stop function, always follow the instructions in the Safe Stop section of the Design Guide.

WARNING

Disconnect all electric power, including remote disconnects. Follow proper lockout/tagout procedures to ensure the power cannot be inadvertently energized. Use an appropriate voltmeter to verify that the unit is discharged. Failure to disconnect power and ensure unit is discharged before servicing could result in death or serious injury.

Also make sure that other voltage inputs have been disconnected, such as external 24 V DC, load sharing (linkage of DC intermediate circuit), as well as the motor connection for kinetic backup.

Systems where adjustable frequency drives are installed must, if necessary, be equipped with additional monitoring and protective devices according to the valid safety regulations, e.g., law on mechanical tools, regulations for the prevention of accidents, etc. Modifications on the adjustable frequency drives by means of the operating software are allowed.

Failure to follow recommendations could result in death or serious injury.

Hoisting applications:

The adjustable frequency drive functions for controlling mechanical brakes cannot be considered as a primary safety circuit. There must always be a redundancy for controlling external brakes.

Once a hardware limit on motor current or DC link voltage is exceeded, the drive will enter “Protection mode”. “Protection mode” means a change of the PWM modulation strategy and a low switching frequency to minimize losses. This continues 10 sec after the last fault and increases the reliability and the robustness of the drive while re-establishing full control of the motor.

In hoist applications, “Protection mode” is not usable because the drive will usually not be able to leave this mode again, and therefore it will extend the time before activating the brake – which is not recommended. "Protection mode” can be disabled by setting par.14-26 Trip Delay at Inverter Fault to zero, which means that the drive will trip immediately if one of the hardware limits is exceeded.

Note

It is recommended to disable protection mode in hoisting applications (par.14-26 Trip Delay at Inverter Fault = 0).

TR200 BACnet

1-7